hi all

[nikhilb]

what is difference between unix filesystem and windows filesystem?
what is differnce between character device and raw device?

[A. Clay Stephenson]

Which UNIX filesystem? Which Windows filesystem? All of them basically do the same thing but are vastly different internally. It would help if you wrote a more focused question.


Character devices are a subset of raw devices which come in two flavors on UNIX: 1)
character -- the i/o occurs directly between the device and the system 2) block --- the i/o is buffered in the buffer cache.

[Dennis Handly]

And it would help if your subject was related to your question so we would know if we are able to answer it.

[Reshma Malusare]

Hi Nikhil,
Its difficult to answer your question in few lines.
1]Features of Unix: If you are familiar with windows FS,then following points may clear your query regarding unix & windows.

* The shell is a command interpreter.
* It also provides an extensive programmable interface.
* The shell is not built into the operating system.
* The shell could be replaced with another program.
* Many command interpreters are available.
* Hierarchical File System --> Information is stored on the disk in containers known as files. Every file is assigned a name,
and a user accesses a file by referencing its name. Files normally contain data, text, programs, and so on. A UNIX system normally contains hundreds of files, so another container, the directory is provided that allows users to organize their files into logical groupings. In the
UNIX system, a directory can be used to store files or other directories.
The file system structure is very flexible, so if a userâ s organizational needs change, files and directories can be easily moved, renamed, or grouped into new or different directories through simple UNIX system commands.
* Multi-tasking
* Multi-user
* Time sharing operating system


2] Device files typically reside in the/dev directory. You can list the device files in this directory with the ll command.Every disk drive has two device files attached to it. The character-type device file is stored in the /dev/rdsk directory and is also called the raw device file. The block-type device file is stored in the /dev/dsk directory.
The very first character in the ll output for a device file indicates the device file type.
Character Device Files --->
A "c" in the first character position identifies a character device file.
Character device files transfer data to the device one character at a time.
Devices such as terminals, printers, plotters, modems, and tape drives are
typically accessed via character device files. Character device files are
sometimes called "raw" device files.

Block Device Files --->

A "b" in the first character position identifies a block device file. When
accessing a device via a block device file, the system reads and writes data
through a buffer in memory, rather than transferring the data directly to device.

Nikhil, all these are very basic questions, you will get more information on
WWW.docs.hp.com. or try to read Hp books like Fundamentals of HP Unix,System administration & networking I & II [SNA I & II]

Thanks & Regards
Reshma